Remove old_implicit_casting setting; use types in queries

[elefeint]

old_implicit_casting works to restore the old lenient behavior in DuckDB 0.10, but we should update the queries to cast instead.

I tested that using casting in the ELSE clause of CASE works:

update books1391973803
SET title = CASE 
  WHEN books_all_varchar.title = 'DONOTUPDATE' 
  THEN books1391973803.title 
  ELSE books_all_varchar.title END,
magic_number = CASE
  WHEN books_all_varchar.magic_number = 'DONOTUPDATE' 
  THEN books1391973803.magic_number 
  ELSE books_all_varchar.magic_number::INTEGER END,
FROM books_all_varchar 
WHERE books_all_varchar.id = books1391973803.id